New thionaphthene-indoleindigo dyestuffs



' wherein R means Patented Apr. '21, 1931 uNiren WILHELM BAUER, or

ANILINE won-Ks, INC., on

WIESDOEIr- OLLTEZE-RHIN'E,

GERMANY, A$S1GNOR TO GENERAL VJ" 1?. 351, A CORPORATION OF DELAWARE iNEW THIONAPHTHENE-IND'OLEINDIGO DYESTUFFS No Drawing. Application filed May 9,

x o 0 o 0 wherein the Xs stand for chlorine or bromine atoms. 7

My new dyestuffs are obtainable by causing a 3-hydroXy-thionaphthene substituted in the 5-position by a halogen atom to react with a 5.7 dihalogen isatin alpha derivative in which the alpha C-atom contains easily removable or replaceable substituents, -for example halogen, a residue of the kind =N-R, an aromatic nucleus, and the like.

The new trihalogen-2-indole-2-thionaphthene indigos are valuable violet dyestuffs exerting unexpected good tastness properties,

. especially to chlorine, washing and light.

The 5halogen-hydrox -thionaphthenes may be obtained in various ways, such as for instance by reacting upon chlorobenzene with chlorosulfonic acid, reducing the para-chlorobenzene sulfonic acid chloride thus obtained to Lmercapto--chlorobenzene, reacting upon the latter with chloroacetic acid as to form para-chlorobenzene-thioglycolic acid and converting this compound into 5-chlorohydroxythionaphthene according to one of the usual methods. In an analogous manner, when starting with bromobenzene, the 5-bromohydroxythionaphthene can be obtained.

The condensation of the 5-halogen-hydroxythionaphthenes with the halogenizatin derivatives above mentioned may be performed in various manners, according to the kind of the isatin derivatives used; Such, for instance, when working with a 5.7-dihalogenizatin-alpha-chloride, the condensation 1929, $eria1 No. 361,839, and in Germany June 12, 1928.

may be effected in anhydrous chlorobenzene, advantageously while heating to temperatures of about 90 C. Or, when working with a 5.7-dihalogenizatin-alpha-arylide, the condensation may advantageously be eifected 50 inacetic anhydride at about 80100 C.

The dyestuffs thus obtainable form violet crystalline powders, difficultly soluble in the usual organic solvents, soluble in strong sulfuric acid with a greenish blue coloration, yielding. with hydrosulfite and caustic soda lye yellow vats from which textile-fibres are dyed clear violet shades of excellent fastness properties. a V

The following examples illustrate my in- 0 vention, without limiting it thereto, the parts being by weight.

Para-chlorophen/yl-thioglycolz c acid Example Z. 10 parts of chlorobenzene are stirred into 35 parts of chlorosulfonic acid at a temperature of about 30 C. As soon as no further reactiontakes place, the para-chol0robenzene sulfonic acid chloride formed is isolated by pouring the reaction mixture on to 7' ice and sucking off. The whole amount of the sultonic acid chloride thus obtained is then reduced by means of 36 parts of strong sulfuric acid, 80 parts of water and 20 parts of zinc powder. The mercapto compound formed during this reduction is separated by steam distillation and dissolved in a sufficient quantity of water with the addition of 7.5 parts of a caustic soda solution of about 33% strength and 6.5 parts of chloroacetic So acid dissolved in water inform of its sodium salt. The reaction mixture is heated to about C. After about one hour the reaction mixture is filtered and acidified with hydrochloric acid, whereby about 12 parts of parachlorophenylioglycolic acid separate.

5-chlorohydrowg thio'naphthene Emample 2-101 partsof para-chlorophe- V nyltiiieglycolic acid are converted into the perature of about 80 C.

mentioned in Example the probable acid chloride by heating in 150 parts of anhydrous chlorobenzene with '22 parts of phosphorus trichloride at the water bath. llhe filtered solution of the chloride thus obtainable is now cooled to about 10 C. and parts of powdered anhydrous alun'iiniumchloride are added, the temperature always being maintained at about 10 C. As soon as the development of hydrochloric acid 10 slackens the temperature is slowly raised to about d0 C. until the develo )ment of hydrochloric acid has completely ceased. N ow the reaction mixture is poured on to ice, the chlorobenzene remored by steam distillation 15 and the separating o-chloro-hydroxythionaphthene is sucked off, washed and purified by dissolving it in dilute soda lye and reprecipitating from the filtered solution by means of carbon dioxide.

Ema/72 176 5.--305 parts or 5.7-dibromoisatin are heated with 225 parts of phosphorus-pentachloride in 3000 parts of anhydrous chlorobenzene to about 110 C. until the formation or" the alpha-chloride oi the dibromoisa- 25 tin is complete.

The reaction mixture is then added to a solution of 200 parts of dried 5-chloro-hydroxythionaphthene in 2000 parts of anhydrous chlorobenzene while stirring at a tem- Atter further stirring for a short time the mixture is cooled to about 50 C. and the dyestuli formed is filtered, washed and dried. It probably c0rresponds to the formula:

It forms a violet crystalline powder, soluble in concentrated sulfuric acid with a greenish blue coloration and dyes textile fibres from a yellow hydrosulfite vat clear violet shades of 5 excellent fastness to chlorine, washing, light and ironing.

When using in this example instead ot 200 parts of 5-chlorohydroxythionaphthene 250 parts of 5-bromo-hydroxythionaphthene a 50 dyestutl of nearly the same properties, but

wherein a; means a chlorine or bromine atom, said products being violet crystalline powders, dyeing textile fibres from a yellow hydrosulfite Vat clear violet shades of good fastness properties, especially to chlorine, washing and light.

'2. As a new product, the vat dyestuff of the probable formula:

said product being a violet crystalline powder, soluble in concentrated sulfuric acid with a greenish blue coloration, dyeing textile fibres from a yellow hydrosulfite vat clear violet shades of excellent fastness properties especially to chlorine, washing, light and iromng.

In testlmony whereof I have hereunto set my hand.

lVILHELM BAUER. [11s.] 

